Estimated agricultural pesticide use for Southeast Stream-Quality Assessment, 2014

Abstract

Introduction One of the goals of the U.S. Geological Survey (USGS) Southeast Stream-Quality Assessment (SESQA) is to characterize contaminants at perennial-stream sites throughout the southern Piedmont and southern Appalachian Mountains. The evaluation of pesticide inputs from agricultural sources will aid in that characterization. Methods used for calculating county-level pesticide use documented in this report are from methods developed and described by Thelin and Stone (2013) and Baker and Stone (2015). Two methods for calculating estimated pesticide use (EPest) rates—EPest-low and EPest-high—were applied in this study to estimate a probable range in the annual amounts of pesticide used for agriculture in 2014. To calculate watershed-level estimates, county-level use was proportionally allocated to agricultural land within each watershed. Concentrations of 262 pesticide compounds were estimated and compiled for subsequent analysis by the USGS National Water Quality Assessment Program, Southeast Stream-Quality Assessment. This report provides estimates of annual agricultural use of 262 pesticide compounds for counties and selected watersheds in parts of eight southeastern States for 2014. Estimates of county- and watershed-level annual agricultural pesticide use are provided as downloadable, tab-delimited files for both EPest-high and EPest-low.